A vehicle seat comprising a pipe frame (reinforcing frame) shaped like a rectangular loop, a plate-like side frame disposed adjacent to a left or right outer side of the pipe frame, and a bracket (force-receiving member) fixed to a left or right outer side of the side frame has hitherto been known in the art (see Patent Literature 1). To be more specific, the side frame is formed to have dimensions such that it protrudes frontward and rearward beyond the pipe frame, and the bracket is disposed in a position on an outer surface of the side frame, such that it substantially covers a front half of the pipe frame as viewed from a lateral direction, and protrudes frontward from the pipe frame.
According to this technique, the bracket is shaped like a box having front, rear, upper and lower sides all of which are flat, and a side collision load imposed on the bracket from outside in a lateral direction is transmitted through these flat sides to the side frame and through the side frame and the pipe frame to a side laterally opposite to that on which the bracket is disposed.
A vehicle seat comprising a seat back frame made of a pipe member shaped like a rectangular frame, a reinforcing member fixed in a position tilted from an upper portion of a laterally outer side of the frame to a lower portion of a laterally inner side of the frame has hitherto been known in the art (see Patent Literature 2). The reinforcing member has outer ends protruding from the frame, and end portions provided with flanges.
In this vehicle seat, as well, a side collision load imposed on one flange from a laterally outer side is transmitted through the reinforcing member and the other flange to a side laterally opposite to a side on which the one flange is provided.